Steam injector



Oct. 16,. 1945. R. D. METCALFE ET'AL 8 STEAM INJECTOR Filed March 27, 1945 2 Sheets-Sheet l R. D. METCALFE ETAL 86, 71

' Oct. 16, 1945.1

' STEAM INJECTOR Filed March 27, 1945 2Sheets-Sheet 2 E /l/l. v .w

112/1; azvZoZf- I J? etc a/Lfe Meta 0Z1??? Patented Oct. 16, 1945 STEAM INJECTOR Richard David Metcalfe and James Croxcn Metcalfe, Romiley, England, assignors to Davies & Metcalfe Limited, Romiley,

British company England, a

Application March 2'7, 1945, Serial No. 585,094 In Great Britain July 17, 1944 3 Claims.

This invention relates to steam injectors and has for its object to provide simple and convenient means for prolonging the efficient life of an injector by allowing the ready renewal of the nozzle parts most subject to wear or erosion.

In accordance with our invention we make the portion of the delivery nozzle at and about its throat and the end portion of the combining nozzle including the main overflow gap adjacent to the delivery nozzle throat in a unitary structure which is removably secured in place between the member providing the diverging delivery end of the delivery nozzle and the member constituting the first portion of the combining nozzle.

The invention further comprises the arrangement wherein the member providing the diverging delivery end of the delivery nozzle screws into the injector casing, and the member constituting the first portion of the combining nozzle screws into the aforesaid member with the unitary structure constituting the throat and the end portion of the combining nozzle having an external flange secured between said members.

Referring to the accompanying explanatory drawings:

Figure 1 is a sectional elevation of a steam injector having its nozzles constructed and arranged in one convenient form in accordance with this invention.

Figure 2 is a detail view of the unitary removable structure which includes parts of the combining and delivery nozzles.

Figure 3 is a sectional elevation of the nozzle system of an injector constructed in accordance with this invention but having a flap type overflow device in the combining nozzle.

The injector comprises the usual steam inlet branch a, water inlet b, overflow outlet and delivery branch (1. There are outer and inner steam nozzles e and 1 which provide a central solid steam jet and an annular steam jet which meets the annular water stream from the water inlet 1).

In Figure 1, the nozzle system of the injector consists of three parts as follows: (1) the first portion of the combining nozzle which at its inlet end g makes a joint with the injector casing 71. at its reduced part i and receives the annular mixed steam and water jet. There is an overflow gap between the portion g and the intermediate part 7' of the first portion of the combining nozzle and a further overflow gap 7c between such intermediate part and the end portion m of the fi portion of the combining nozzle, (2) the unitary structure (shown in detail to an enlarged scale in Figure 2) comprising the end portion n of the converging combining nozzle and the throat or Venturi portion 0 of the delivery nozzle and (3) the diverging delivery nozzle 10.

There is a gap q between the portions m and 'n of the combining nozzle, a gap 1' (which is the main overflow gap) between the end portion n of the combining nozzle and the throat portion 0 and a further gap s between the delivery nozzle p andthe throat portion 0.

The first portion of the Combining nozzle has finger like extensions t which are united by an externally threaded ring u which screws into an internally threaded part 1} of the delivery nozzle portion of the nozzle system. The part '0 is also externally threaded to screw into the injector casing at 20 which divides the overflow compartment :r from the delivery branch (1 of the injector.

The throat portion 0 of the nozzle system has an external flange y which is clamped between a shoulder a on the delivering nozzle portion 10 and the end of the ring it on the first portion of the combining nozzle.

With the arrangement shown, the complete nozzle system can be withdrawn from the injector casing when the cover 2 is removed from the delivery end of the injector. Such nozzle system can then be divided into its three components and the throat portion 0 (including the last part n of the combining nozzle and the main overflow gap at T) which is most subject to wear, renewed if required. There is the usual overflow valve 3 on the overflow chamber :13.

In the Figure 3 construction, there is a flap 5 pivotally carried upon a swing lever 6 for allowing overflow from the combining nozzle 1 at starting. The unitary structure which comprises the end portion 8 of the converging combining nozzle, the main overflow gap 9 and the throat or Venturi portion Ill of the delivery nozzlejis substantially the same as shown in Figure 2 but it is secured in place by screwing directly into the delivery nozzle portion II of the injector.

What we claim'ist 1. In a steam injector, a casing; a delivery nozzle in said casing having a diverging delivery end and a portion forming a throat, a combining nozzle having a first portion and an end portion so arranged with respect to the throat portion of the delivery nozzle as will provide a main overflow gap, the throat portion and the end portion including said overflow gap constituting a unitary structure removably secured between the first ing an external flange secured between the delivery end and said first portion.

3. In a steam injector as claimed in claim 1, the arrangement in which the unitary structure 5 screws into the delivery end of the delivery nozzle.

RICHARD DAVID METCALFE. JAMES CROXON METCALFE. 

